Fig. 2: Transient embryonic shh pulse disrupts caudal fin development in a local and dose-dependent manner.

(A) shh pulse results in truncate fin development when zebrafish are heat shock induced on 2 or 3 dpf. Significance determined by ANOVA followed by Tukey’s post hoc test. (B) Overexpression of shh during hours following heat shock. Significance determined using Welch’s two-sample T-tests, and the correlation between readout and time following heat shock determined by linear-mixed effects model. (C-E) Locally induced shha pulse is sufficient to induce truncate phenotype. (C-C’) Embryo subjected to local posterior heat shock at 2 dpf did not show GFP fluorescence and grew into an adult with a forked fin. (D-D’) Local posterior heat shock induced GFP in transgenic embryo (brackets), which grew into an adult with a truncate fin.Scale bars, 500µm. (E) Local posterior heat shocks in transgenic embryos are capable of inducing truncate fin shape. Inducing local shh pulse in the anterior of the embryo produces no change in fin shape. Significance determined by ANOVA followed by Tukey’s post hoc test. (F) Fish sorted by relative brightness of GFP expression 1 day after whole-body HS (4 dpf) show different caudal fin shapes as adults. Shown below the graph are representative images of individuals in each brightness category. Significance determined by ANOVA followed by Tukey’s post hoc test. Scale bar, 1 mm. (G) Quantified copy number of GFP transgene amplified from genomic DNA correlates with caudal fin shape. Significance between mean Rq and caudal fin shape is determined by linear-mixed effects model.